| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Aerospace Medical Research Unit, Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada
Submitted 27 November 2002; accepted in final form 6 March 2003
Eye-head (EH) neurons within the medial vestibular nuclei are thought to be the primary input to the extraocular motoneurons during smooth pursuit: they receive direct projections from the cerebellar flocculus/ventral paraflocculus, and in turn, project to the abducens motor nucleus. Here, we recorded from EH neurons during head-restrained smooth pursuit and head-unrestrained combined eye-head pursuit (gaze pursuit). During head-restrained smooth pursuit of sinusoidal and step-ramp target motion, each neuron's response was well described by a simple model that included resting discharge (bias), eye position, and velocity terms. Moreover, eye acceleration, as well as eye position, velocity, and acceleration error (error = target movement – eye movement) signals played no role in shaping neuronal discharges. During head-unrestrained gaze pursuit, EH neuron responses reflected the summation of their head-movement sensitivity during passive whole-body rotation in the dark and gaze-movement sensitivity during smooth pursuit. Indeed, EH neuron responses were well predicted by their head- and gaze-movement sensitivity during these two paradigms across conditions (e.g., combined eye-head gaze pursuit, smooth pursuit, whole-body rotation in the dark, whole-body rotation while viewing a target moving with the head (i.e., cancellation), and passive rotation of the head-on-body). Thus our results imply that vestibular inputs, but not the activation of neck proprioceptors, influence EH neuron responses during head-on-body movements. This latter proposal was confirmed by demonstrating a complete absence of modulation in the same neurons during passive rotation of the monkey's body beneath its neck. Taken together our results show that during gaze pursuit EH neurons carry vestibular- as well as gaze-related information to extraocular motoneurons. We propose that this vestibular-related modulation is offset by inputs from other premotor inputs, and that the responses of vestibuloocular reflex interneurons (i.e., position-vestibular-pause neurons) are consistent with such a proposal.
This article has been cited by other articles:
|
|
 |
|
  M. R. Van Horn, P. A. Sylvestre, and K. E. Cullen The Brain Stem Saccadic Burst Generator Encodes Gaze in Three-Dimensional Space J Neurophysiol, May 1, 2008; 99(5): 2602 - 2616. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Haque, M. Zakir, and J. D. Dickman Recovery of Gaze Stability During Vestibular Regeneration J Neurophysiol, February 1, 2008; 99(2): 853 - 865. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Beraneck and K. E. Cullen Activity of Vestibular Nuclei Neurons During Vestibular and Optokinetic Stimulation in the Alert Mouse J Neurophysiol, September 1, 2007; 98(3): 1549 - 1565. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. G. Sadeghi, L. B. Minor, and K. E. Cullen Response of Vestibular-Nerve Afferents to Active and Passive Rotations Under Normal Conditions and After Unilateral Labyrinthectomy J Neurophysiol, February 1, 2007; 97(2): 1503 - 1514. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Cullen and J. E. Roy Signal Processing in the Vestibular System During Active Versus Passive Head Movements J Neurophysiol, May 1, 2004; 91(5): 1919 - 1933. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. J. Krauzlis Recasting the Smooth Pursuit Eye Movement System J Neurophysiol, February 1, 2004; 91(2): 591 - 603. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. Sylvestre, J. T. L. Choi, and K. E. Cullen Discharge Dynamics of Oculomotor Neural Integrator Neurons During Conjugate and Disjunctive Saccades and Fixation J Neurophysiol, August 1, 2003; 90(2): 739 - 754. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
